Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/08—Processes
  • C08G18/16—Catalysts
  • C08G18/166—Catalysts not provided for in the groups C08G18/18 - C08G18/26
  • C08G18/168—Organic compounds
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D263/00—Heterocyclic compounds containing 1,3-oxazole or hydrogenated 1,3-oxazole rings
  • C07D263/02—Heterocyclic compounds containing 1,3-oxazole or hydrogenated 1,3-oxazole rings not condensed with other rings
  • C07D263/08—Heterocyclic compounds containing 1,3-oxazole or hydrogenated 1,3-oxazole rings not condensed with other rings having one double bond between ring members or between a ring member and a non-ring member
  • C07D263/16—Heterocyclic compounds containing 1,3-oxazole or hydrogenated 1,3-oxazole rings not condensed with other rings having one double bond between ring members or between a ring member and a non-ring member with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
  • C07D263/18—Oxygen atoms
  • C07D263/20—Oxygen atoms attached in position 2
  • C07D263/22—Oxygen atoms attached in position 2 with only hydrogen atoms or radicals containing only hydrogen and carbon atoms, directly attached to other ring carbon atoms
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/003—Polymeric products of isocyanates or isothiocyanates with epoxy compounds having no active hydrogen
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/08—Processes
  • C08G18/16—Catalysts
  • C08G18/22—Catalysts containing metal compounds
  • C08G18/227—Catalysts containing metal compounds of antimony, bismuth or arsenic
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/70—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the isocyanates or isothiocyanates used
  • C08G18/72—Polyisocyanates or polyisothiocyanates
  • C08G18/74—Polyisocyanates or polyisothiocyanates cyclic
  • C08G18/76—Polyisocyanates or polyisothiocyanates cyclic aromatic
  • C08G18/7614—Polyisocyanates or polyisothiocyanates cyclic aromatic containing only one aromatic ring
  • C08G18/7621—Polyisocyanates or polyisothiocyanates cyclic aromatic containing only one aromatic ring being toluene diisocyanate including isomer mixtures

Definitions

• the present invention relates to a method for the selective production of oxazolidinone compounds comprising the step of reacting an isocyanate compound with an epoxide compound in the presence of an onium salt as catalyst and to the oxazolidinone compounds obtainable by said method.
• the invention further relates to a method for the production of oligooxazolidinone and/or polyoxazolidinone compounds, comprising the step of reacting a polyisocyanate compound with a polyepoxide compound in the presence of said catalyst.
• the invention further relates to oxazolidinone, oligooxazolidinone and/or polyoxazolidinone compounds with a regioselectivity to the 5-substituted l,3-oxazolidin-2-one regioisomer of > 78 %.
• Oxazolidinones are widely used structural motifs in pharmaceutical applications, and the cycloaddition of epoxides and isocyanates seems to be a convenient one-pot synthetic route to produce them. Expensive catalysts, reactive polar solvents, long reaction times and low chemoselectivities are common in early reports for the synthesis of oxazolidinones (M. E. Dyen and D. Swern, Chem. Rev., 67, 197 (1967); X. Zhang and W. Chen, Chem. Lett., 39, 527 (2010); M.T. Barros and A.M.F. Phillips, Tetrahedron: Asymmetry, 21, 2746 (2010); H.-Y. Wu, J.-C.
• Unpublished European Patent Application No. 12192611.7 relates to a method for the production of oxazolidinone compounds, comprising the step of reacting an isocyanate compound with an epoxide compound in the presence of a Lewis acid catalyst.
• a Lewis acid catalyst The use of onium catalysts is disclosed. But neither activities nor selectivities with regard to the substitution pattern of the onium salts have been disclosed.
• an antimony catalyst Pl SbBr
• EP 0296450 discloses a method for the production of oligomeric oxazolidinone containing polyepoxides from bisepoxides and diisocyanates. It is required that the used bisepoxides carry hydroxy-groups corresponding to an OH-number of at least 2 and the molar ratio between the epoxide and isocyanate group within the diepoxides and diisocyanates is 1.4 up to 2.5. The reaction is carried out at temperatures between 140°C and 180°C.
• the catalysts claimed are alkyl- and aryl- substituted phosphonium salts; in the examples tetrabutylphosphonium bromide and benzyltriphenylphosphonium bromide are used.
• EP 0343064 discloses a method for preparing a thermosettable resin from polyisocyanate, polyepoxide and catalyst.
• the catalysts used are tin compounds as well as stibonium and phosphonium salts.
• a high selectivity to oxazolidinone in comparison to isocyanurate is observed.
• the regioselectivity is not discussed.
• US 3687897 discloses a process for the preparation of oxazolidinones by reacting an isocyanate with an epoxide in presence of a phosphonium catalyst such as tetrabutylphosphonium bromide.
• a phosphonium catalyst such as tetrabutylphosphonium bromide.
• the examples disclose the use of a tetrabutylphosphonium bromide or iodide catalyst.
• the influence of the substituents on the phosphonium salt has not been discussed.
• Phosphonium salts having three phenyl substituents at the phosphorous atom are deemed inactive with regard to the reaction of isocyanate and epoxide. The regio- and chemoselectivity of the reaction is not discussed.
• WO 86/06734 Al discloses a process for the preparation of polyisocyanurate-based polyoxazolidinone polymers containing relatively small proportions of trimerized polyisocyanates.
• the amount of isocyanurate compounds is below 15 mol-%.
• the catalysts used are organoantimony iodide salts. The regioselectivity of the reaction is not discussed.
• Such undesired side reactions include for example the trimerisation of isocyanate to isocyanurate groups, the formation of carbodiimides and homo-polymers of the epoxides.
• the specifications concerning a high chemoselectivity to the oxazolidinone compound are particularly stringent, if polyoxazolidinone compounds with an almost linear polymer backbone and thermoplastic properties are desired.
• the formation of isocyanurate groups should be supressed as this side reaction may result in crosslinking of the polymer chains.
• the use of such special onium salts leads to a high rate in the reaction of isocyanates and epoxides and enables the production of the oxazolidinone compounds with high chemoselectivity in combination with the desired regioselectivity towards the 5-substituted l,3-oxazolidin-2-one regioisomer of > 78 %.
• the substitution pattern of the onium cation determines the activity and selectivity of the catalysts.
• the subject matter of the present invention is a method for the production of oxazolidinone compounds, comprising the step of reacting an isocyanate compound with an epoxide compound in the presence of a catalyst, characterized in that the catalyst is represented by the general formula (I)
• M is phosphorous or antimony
• Rl), (R2), (R3), (R4) are independently of one another selected from the group comprising linear or branched alkyl groups containing 1 to 22 carbon atoms, optionally substituted with heteroatoms and/or heteroatom containing substituents, cycloaliphatic groups containing 3 to 22 carbon atoms, optionally substituted with heteroatoms and/or heteroatom containing substituents, CI to C3 alkyl- bridged cycloaliphatic groups containing 3 to 22 carbon atoms, optionally substituted with heteroatoms and/or heteroatom containing substituents and aryl groups containing 6 to 18 carbon atoms, optionally substituted with one or more alkyl groups containing 1 to 10 carbon atoms and/or heteroatom containing substituents and/or heteroatoms,
• (R4) is different from (Rl), (R2), and (R3) and
• branched alkyl groups containing 3 to 22 carbon atoms preferably 3 to 6 carbon atoms, particularly preferred 4 carbon atoms, cycloaliphatic groups containing 3 to 22 carbon atoms, preferably 3 to 15 carbon atoms, particularly preferred 3 to 8 carbon atoms, CI to C3 alkyl-bridged cycloaliphatic groups containing 3 to 22 carbon atoms, preferably 3 to 15 carbon atoms, particularly preferred 3 to 12 carbon atoms and aryl groups, containing 6 to 18 carbon atoms, optionally substituted with one or more alkyl groups containing 1 to 10 carbon atoms and/or heteroatom containing substituents and/or heteroatoms,
• (Rl), (R2) are aryl groups containing 6 to 18 carbon atoms preferably 6 carbon atoms,
• Y is a halide, carbonate, nitrate, sulphate or phosphate anion and
• n is an integer of 1, 2 or 3.
• oxazolidinone compound is meant to denote oxazolidinone compounds obtainable by the reaction of an isocyanate compound with an epoxide compound.
• oxazolidinone compound is meant to include polyoxazolidinone compounds with at least two oxazolidinone moieties in the molecule obtainable by the reaction of a polyisocyanate with a polyepoxide.
• isocyanate compound is meant to denote monoisocyanate compounds, polyisocyanate compounds (having two or more NCO groups), NCO-terminated biuret, isocyanurates, uretdiones, carbamates and NCO-terminated prepolymers.
• monoisocyanate compound is meant to denote isocyanate compounds having one isocyanate group.
• polyisocyanate compound is meant to denote isocyanate compounds having at least two isocyanate groups.
• diisocyanate compound is meant to denote polyisocyanate compounds having two isocyanate groups.
• epoxide compound is meant to denote monoepoxide compounds, polyepoxide compounds (having two or more epoxide groups) and epoxide terminated prepolymers.
• monoepoxide compound is meant to denote epoxide compounds having one epoxy group.
• polyepoxide compound is meant to denote epoxide compounds having at least two epoxy groups.
• diepoxide compound is meant to denote epoxide compounds having two epoxy groups.
• onium salt is meant to denote the combination of a particular phosphonium and stibonium cation with a suitably chosen anion.
• Suitable monoisocyanate compounds are methyl isocyanate, ethyl isocyanate, n-propyl isocyanate, isopropyl isocyanate, n-butyl isocyanate, isobutyl isocyanate, tert-butyl isocyanate, n- pentyl isocyanate, n-hexyl isocyanate, cyclohexyl isocyanate, ⁇ -chlorohexamethylene isocyanate, n-heptyl isocyanate, n-octyl isocyanate, iso-octyl isocyanate, 2-ethyl hexyl isocyanate, 2-norbornyl methyl isocyanate, nonyl isocyanate, 2,3,4-trimethylcyclohexyl isocyanate, 3,3,5- trimethylcyclohexyl isocyanate, decyl isocyanate, undecyl iso
• Preferred monoisocyanate compounds are benzyl isocyanate, phenyl isocyanate, ortho-, meta-, para-tolyl isocyanate, dimethylphenyl isocyanate (technical mixture and individual isomers), 4- cyclohexylphenyl isocyanate and ortho-, meta-, /jara-methoxyphenyl isocyanate.
• a mixture of two or more of the aforementioned monoisocyanate compounds can also be used.
• polyisocyanate compounds are tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), 2-methylpentamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate (THDI), dodecamethylene diisocyanate, 1 ,4-diisocyanatocyclohexane, 3- isocyanatomethyl-3,3,5-trimethylcyclohexyl isocyanate (isophorone diisocyanate, IPDI), 4,4'- diisocyanatodicyclohexylmethane (H12-MDI), 4,4'-diisocyanato-3,3'-dimethyldicyclohexylmethane, 4,4'-diisocyanato-2,2-dicyclohexylpropane, poly(hexamethylene diisocyanate), octamethylene diisocyanate, tolylene-a,4-diisocyanate,
• Preferred polyisocyanates are hexamethylene diisocyanate (HDI), 3-isocyanatomethyl-3,3,5- trimethylcyclohexyl isocyanate (isophorone diisocyanate, IPDI), 4,4'- diisocyanatodicyclohexylmethane (H12-MDI), 2,4- or 2,5- or 2,6-diisocyanatotoluene (TDI) or mixtures of these isomers, 4,4'-, 2,4'- or 2,2'-diisocyanatodiphenylmethane (MDI) or mixtures of these isomers.
• HDI hexamethylene diisocyanate
• IPDI isophorone diisocyanate
• H12-MDI 4,4'- diisocyanatodicyclohexylmethane
• TDI 2,4- or 2,5- or 2,6-diisocyanatotoluene
• MDI 4,4
• a mixture of two or more of the aforementioned polyisocyanates can also be used.
• monoepoxide compounds are ethylene oxide, propylene oxide, 1,2-butene oxide, 2,3- butene oxide, butadiene monoepoxide, 1,2-hexene oxide, cyclohexene oxide, vinylcyclohexene monoxide, limonene monoxide, oxides of C10 - C18 alpha-olefins, styrene oxide, the epoxides of unsaturated fatty acid CI - CI 8 alkyl esters, methyl glycidyl ether, ethyl glycidyl ether, propyl glycidyl ether, butyl glycidyl ether, pentyl glycidyl ether, hexyl glycidyl ether, cyclohexyl glycidyl ether, octyl glycidyl ether, 2-ethylhexyl glycidyl
• Preferred monoepoxide compounds are ethylene oxide, propylene oxide, 1,2-butene oxide, 2,3- butene oxide, styrene oxide, butyl glycidyl ether, benzyl glycidyl ether, phenyl glycidyl ether, p- tolyl glycidyl ether, 4-tert-butylphenyl glycidyl ether.
• a mixture of the aforementioned monoepoxide compounds can also be used.
• Diepoxide compounds are for example butadiene diepoxide, vinylcyclohexene diepoxide, limonene diepoxide, the diepoxides of double unsaturated fatty acid CI - CI 8 alkyl esters, ethylene glycol diglycidyl ether, di(ethylene glycol) diglycidyl ether, poly(ethylene glycol) diglycidyl ether, propylene glycol diglycidyl ether, di(propylene glycol) diglycidyl ether, poly(propylene glycol) diglycidyl ether, neopentyl glycol diglycidyl ether, polybutadiene diglycidyl ether, 1,6-hexanediol diglycidyl ether, hydrogenated bisphenol-A diglycidyl ether, 1 ,2-dihydroxybenzene diglycidyl ether, resorcinol diglycidyl ether, 1 ,4-dihydroxy
• Preferred diepoxide compounds are butadiene diepoxide, the diepoxides of double unsaturated fatty acid CI - CI 8 alkyl esters, ethylene glycol diglycidyl ether, di(ethylene glycol) diglycidyl ether, poly(ethylene glycol) diglycidyl ether, propylene glycol diglycidyl ether, di(propylene glycol) diglycidyl ether, poly(propylene glycol) diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6- hexanediol diglycidyl ether, hydrogenated bisphenol-A diglycidyl ether, 1 ,2-dihydroxybenzene diglycidyl ether, resorcinol diglycidyl ether, 1 ,4-dihydroxybenzene diglycidyl ether, bisphenol-A diglycidyl ether, diglycidyl o-phthalate,
• a mixture of two or more the aforementioned diepoxides can also be used.
• Polyepoxide compounds are for example glycerol polyglycidyl ether, trimethylolpropane polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, polyglycerol polyglycidyl ether, sorbitol polyglycidyl ether.
• a mixture of one or more polyepoxide compounds and/or one or more of the aforementioned diepoxide compounds can also be used.
• Onium salts within the scope of the invention are salts represented by formula (I)
• M is phosphorous or antimony
• Rl), (R2), (R3), (R4) are independently of one another selected from the group comprising linear or branched alkyl groups containing 1 to 22 carbon atoms, optionally substituted with heteroatoms and/or heteroatom containing substituents, cycloaliphatic groups containing 3 to 22 carbon atoms, optionally substituted with heteroatoms and/or heteroatom containing substituents, CI to C3 alkyl- bridged cycloaliphatic groups containing 3 to 22 carbon atoms, optionally substituted with heteroatoms and/or heteroatom containing substituents and aryl groups containing 6 to 18 carbon atoms, optionally substituted with one or more alkyl groups containing 1 to 10 carbon atoms and/or heteroatom containing substituents and/or heteroatoms,
• (R4) is different from (Rl), (R2), and (R3) and
• branched alkyl groups containing 3 to 22 carbon atoms preferably 3 to 6 carbon atoms, particularly preferred 4 carbon atoms, cycloaliphatic groups containing 3 to 22 carbon atoms, preferably 3 to 15 carbon atoms, particularly preferred 3 to 8 carbon atoms CI to C3 alkyl-bridged cycloaliphatic groups containing 3 to 22 carbon atoms, preferably 3 to 15 carbon atoms, particularly preferred 3 to 12 carbon atoms and aryl groups, containing 6 to 18 carbon atoms, optionally substituted with a heteroatom containing group, whereas
• (Rl), (R2) are aryl groups containing 6 to 18 carbon atoms preferably 6 carbon atoms,
• Y is a halide, carbonate, nitrate, sulphate or phosphate anion and
• n is an integer of 1, 2 or 3.
• M of formula (I) is phosphorous.
• (Rl), (R2), (R3) of formula (I) independently of one another are aryl groups containing 6 to 18 carbon atoms, preferably (Rl), (R2), (R3) of formula (I) are each phenyl groups.
• (R4) of formula (I) is selected from the group comprising branched alkyl groups containing 3 to 6 carbon atoms, cycloaliphatic groups containing 3 to 8 carbon atoms, CI to C3 alkyl-bridged cycloaliphatic groups containing 1 to 12 carbon atoms and aryl groups, containing 6 to 18 carbon atoms, optionally substituted with a heteroatom containing group.
• R4 of formula (I) is selected from the group comprising branched alkyl groups containing 3 to 6 carbon atoms, cycloaliphatic groups containing 3 to 8 carbon atoms, CI to C3 alkyl-bridged cycloaliphatic groups containing 3 to 12 carbon atoms and aryl groups, containing 6 carbon atoms which are substituted with a heteroatom containing group.
• R4 of formula (I) is selected from the group comprising branched alkyl groups containing 3 to 6 carbon atoms, cycloaliphatic groups containing 3 to 8 carbon atoms, CI to C3 alkyl-bridged cycloaliphatic groups containing 3 to 12 carbon atoms and phenyl, substituted with at least one heteroatom containing group, wherein the heteroatom is selected from O, N and/or S.
• R4 of formula (I) is selected from the group comprising of branched alkyl groups containing 3 to 6 carbon atoms, cycloaliphatic groups containing 3 to 8 carbon atoms, CI to C3 alkyl-bridged cycloaliphatic groups containing 3 to 12 carbon atoms and phenyl, substituted with a O-methyl, O-ethyl, O-propyl, O-butyl, O-phenyl, N-(methyl)2-, N- (ethyl)2-, N-(phenyl)2, S- methyl, S-ethyl, S-propyl, S-butyl, or S-phenyl- group.
• R4 of formula (I) is selected from z-propyl, z-butyl, sec- butyl, i-butyl, n-pentyl, z o-pentyl, neo-pentyl, n-hexyl, 2-hexyl, 3-hexyl, 2-ethyl-hexyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, CH 2 -cyclopentyl, CH 2 -cyclohexyl, CH 2 - cycloheptyl, CH 2 -norbornyl, CH 2 -bicyclo-[2.2.1]-heptyl, CH 2 -adamantyl, CH 2 -bicyclo-[2.2.2]- octyl, CH 2 -twistyl, CH 2 -bicyclo-[3.3.3]-undecyl,
• a catalyst of formula (I) is used, wherein M is phosphorous, ( l), (R2) and (R3) are each phenyl groups and
• R4 is selected from the group comprising branched alkyl groups containing 3 to 22 carbon atoms, preferably 3 to 6 carbon atoms, particularly preferred 4 carbon atoms, cycloaliphatic groups containing 3 to 22 carbon atoms, preferably 3 to 15 carbon atoms, particularly preferred 3 to 8 carbon atoms, CI to C3 alkyl-bridged cycloaliphatic groups containing 3 to 22 carbon atoms, preferably 3 to 15 carbon atoms, particularly preferred 3 to 12 carbon atoms and aryl groups, containing 6 to 18 carbon atoms, optionally substituted with a heteroatom containing group,
• Y is a halide, carbonate, nitrate, sulphate or phosphate anion, preferably a halide or carbonate anion, more preferred chloride, bromide or carbonate and
• n is an integer of 1, 2 or 3.
• M is phosphorous
• (Rl), (R2) and (R3) are each phenyl groups and
• R4 is selected from the group comprising z ' -propyl, z ' -butyl, sec-butyl, i-butyl, n-pentyl, z o-pentyl, neo-pentyl, n-hexyl, 2-hexyl, 3-hexyl, 2-ethyl-hexyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, CH2-cyclopentyl, CH2-cyclohexyl, CH2-cycloheptyl, CH2-norbornyl, CH2-bicyclo- [2.2.1]-heptyl, CH 2 -adamantyl, CH 2 -bicyclo-[2.2.2]-octyl, CH 2 -twistyl, CH 2 -bicyclo-[3.3.3]- undecyl, 2-methoxyphenyl, 4-methoxypheny
• Y is a halide, carbonate, nitrate, sulphate or phosphate anion, preferably a halide or carbonate anion, more preferred chloride, bromide or carbonate and
• n is an integer of 1, 2 or 3.
• M is phosphorous
• (Rl), (R2) and (R3) are each phenyl groups and
• (R4) is selected from the group comprising cyclopentyl, cyclohexyl, CH2-adamantyl, 2- methoxyphenyl and 4-methoxyphenyl,
• Y is a halide, carbonate, nitrate, sulphate or phosphate anion, preferably a halide or carbonate anion, more preferred chloride, bromide or carbonate and
• n is an integer of 1, 2 or 3.
• the isocyanate compound is selected from benzyl isocyanate, phenyl isocyanate, ortho-, meta-, para-tolyl isocyanate, dimethylphenyl isocyanate (technical mixture and individual isomers), 4-cyclohexylphenyl isocyanate and/or ortho-, meta-, /jara-methoxyphenyl isocyanate and the epoxide compound is selected from ethylene oxide, propylene oxide, 1,2-butene oxide, 2,3- butene oxide, styrene oxide, butyl glycidyl ether, benzyl glycidyl ether, phenyl glycidyl ether, p- tolyl glycidyl ether and/or 4-tert-butylphenyl glycidyl ether.
• the diisocyanate compound is selected from hexamethylene diisocyanate (HDI), 3- isocyanatomethyl-3,3,5-trimethylcyclohexyl isocyanate (isophorone diisocyanate, IPDI), 4,4'- diisocyanatodicyclohexylmethane (H12-MDI), 2,4- or 2,5- or 2,6-diisocyanatotoluene (TDI) or mixtures of these isomers and/or 4,4'-, 2,4'- or 2,2'-diisocyanatodiphenylmethane (MDI) or mixtures of these isomers and the diepoxide compound is selected from butadiene diepoxide, the diepoxides of double unsaturated fatty acid CI - CI 8 alkyl esters, ethylene glycol diglycidyl ether, di( ethylene glycol) diglycid
• the method according to the invention is performed in the presence of a solvent.
• Suitable solvents are high-boiling non-protic solvents such as N-methylpyrrolidone (NMP), N-ethylpyrrolidone, cyclic ethylene carbonate, cyclic propylene carbonate, sulfolane, chlorobenzene, the different isomers of dichlorobenzene, the different isomers of trichlorobenzene, decalin, hexamethylphosphoramide, dimethylformamide, N,N-dimethylacetamide (DMAc), dimethyl sulfoxide or mixtures of one or more of the aforementioned solvents among each other or with further non-protic solvents.
• Preferred solvents are NMP, sulfolane and DMAc.
• the reaction is conducted in the absence of a solvent.
• the reaction mixture contains only the epoxide compound(s), the isocyanate compound(s) and the onium salt(s) as well as the oxazolidinone compound formed during the reaction.
• the isocyanate compound may be added to the epoxide compound in a continuous or step-wise manner with two or more individual addition steps in the step-wise addition wherein in each individual addition step the amount of isocyanate compound added is ⁇ 50 weight-% of the total amount of isocyanate compound to be added.
• This is to be understood in such a way that during the course of the reaction the isocyanate compound is added to the reaction mixture containing the epoxide compound continuously or in the aforementioned step-wise manner. Included is also the case that the isocyanate compound is added via a syringe pump, dripping funnel or other continuous or semi-continuous devices where the isocyanate is brought into the reaction mixture.
• the reaction should be essentially complete shortly after the end of the addition of the isocyanate compound.
• the isocyanate compound is added continuously to the reaction mixture.
• Continuous in the meaning of the invention means that the isocyanate compound is added to the reaction mixture over a defined period of time, while at the same time any isocyanate compound present in the reaction mixture is converted to the oxazolidinone compound.
• the rate of isocyanate addition is smaller than or equal to the maximum rate, with which the isocyanate compound can be converted under these reaction conditions to the oxazolidinone compound in order to avoid accumulation of NCO groups in the reaction mixture.
• the actual concentration of NCO groups in the reaction mixture may be observed, for example, by in-situ IR spectroscopy. If the NCO group concentration is observed to increase above a set value, the rate of isocyanate addition is reduced.
• the isocyanate compound is added to the reaction mixture (consisting of epoxide compound, isocyanate compound, onium salt and oxazolidinone compound, but not considering solvent, if present) with such an addition rate that the concentration of the isocyanate compound in the reaction mixture is ⁇ 40 weight-%, preferably ⁇ 20 weight-% and more preferred ⁇ 15 weight-%.
• the amount of isocyanate compound added in each individual addition step is > 0.1 weight-% to ⁇ 50 weight-% of the total amount of isocyanate compound to be added.
• the amount of isocyanate compound added per individual addition step is > 1.0 weight- %> to ⁇ 40 weight-%>, more preferred > 5.0 weight-%) to ⁇ 35 weight- %> of the total amount of isocyanate compound to be added.
• the time intervals between each individual addition of isocyanate compound to the reaction mixture is chosen in such a way that the concentration of the isocyanate compound in the reaction mixture at any given point in time is ⁇ 40 weight-%, preferably ⁇ 20 weight-% and more preferred ⁇ 15 weight-%.
• the actual concentration of NCO groups in the reaction mixture may be observed, for example, by in-situ IR spectroscopy. If the NCO group concentration is observed to increase above a set value, the time interval between the addition steps is increased.
• the isocyanate compound is an isocyanate compound with two or more NCO groups per molecule, preferably with two NCO groups per molecule
• the epoxide compound is an epoxide compound with two or more epoxy groups per molecule, preferably with two epoxide groups per molecule.
• the method according to the invention is performed for example at temperatures of > 130 °C to
• ⁇ 280 °C preferably at a temperature of > 140 °C to ⁇ 240 °C, most preferred at a temperature of ⁇ 155 °C to ⁇ 210 °C.
• the catalyst according to formula (I) is present in an amount of > 0.0001 mol-%> to ⁇ 2.0 mol-%>, relative to the amount of isocyanate compound to be added to the reaction mixture.
• the catalyst is present in an amount of > 0.001 mol-%> to
• the oxazolidinone product is obtained with a chemoselectivity SOXA, given as the ratio of the molar amount of oxazolidinone moieties to the sum of the molar amount of oxazolidinone moieties and the molar amount of isocyanurate groups, of > 88 %>, preferably > 95 % and particularly preferred > 99 %.
• the molar ratio can be determined, for example, using high performance liquid chromatography (HPLC) or NMR spectroscopy.
• HPLC high performance liquid chromatography
• NMR spectroscopy One method for determining the chemoselectivity SOXA is described below in the methods.
• the oxazolidinone product is obtained with a regioselectivity towards the 5-substituted l,3-oxazolidin-2-one regioisomer of > 78 %>, preferably > 80 % and particularly preferred > 88 %.
• the regioselectivity RS-OXA is given as the ratio of the molar fraction of 5-substituted l,3-oxazolidin-2-one moieties to the sum of the molar fractions of 5-substituted and 4-substituted l,3-oxazolidin-2-one moieties.
• the molar fraction of the 5-substituted and 4-substituted l ,3-oxazolidin-2-one regioisomers can be determined, for example, using high performance liquid chromatography (HPLC) or NMR spectroscopy.
• HPLC high performance liquid chromatography
• NMR spectroscopy One method for determining the regioselectivity RS-OXA is described below in the methods.
• the present invention is further directed towards an oligomeric or polymeric oxazolidinone compound, obtainable by a method according to the invention using an isocyanate compound with at least two NCO groups per molecule, preferably two NCO groups per molecule, and an epoxide compound with at least two epoxy groups per molecule, preferably two epoxy groups per molecule, comprising at least one unit derived from the isocyanate compound and at least two units derived from the epoxide compound or comprising at least one unit derived from the epoxide compound and at least two units derived from the isocyanate compound.
• the chain length of the polyoxazolidinone compounds can be controlled by adjusting the ratio between the diisocyanate and the diepoxide compound.
• An isocyanate terminated oligomer is obtained, when the diisocyanate is employed in excess.
• An epoxide terminated oligomer is obtained, when the diepoxide is employed in excess.
• Linear polymer chains with high molecular weight are obtained, when equimolar amounts of diisocyanate and diepoxide are reacted with one another.
• the precise content of isocyanate and epoxide groups in the diisocyanate and diepoxide, respectively, are preferentially determined before the polymerisation reaction, e.g., by measuring the isocyanate number according to German standard norm DIN EN ISO 11909 and the epoxide number according to German standard norm DIN EN 1877-1.
• the number average molecular weight M n of the polyoxazolidinone compound may be, for example, in the range of > 320 g/mol to ⁇ 10 ⁇ 00 ⁇ 00 g/mol, preferably > 480 g/mol to ⁇ 600 ⁇ 00 g/mol and most preferably > 2 ⁇ 00 g/mol to ⁇ 200 ⁇ 00 g/mol, as determined with gel permeation chromatography (GPC).
• GPC gel permeation chromatography
• Another method suitable to determine the molecular weight of the polyoxazolidinone compounds is based on end-group analysis with 'H-NMR spectroscopy.
• An alternative method to control the molecular weight of the products constitutes in adding a small amount of a monoepoxide or monoisocyanate to the mixture of polyepoxide and the polyisocyanate compound.
• the monoepoxide or monoisocyanate compound can be added at the beginning of the reaction of polyepoxide and polyisocyanate compound, during the reaction of polyepoxide and polyisocyanate compound or after the reaction of polyepoxide and polyisocyanate compound is completed.
• this oligomeric or polymeric oxazolidinone compound comprises at least one, preferably at least two and particularly preferred two terminal epoxide and/or isocyanate groups. It is also possible that this oligomeric or polymeric oxazolidinone compound comprises at least one terminal group which is non-reactive towards epoxide and/or isocyanate groups. Examples include alkoxy groups or trialkylsiloxane groups.
• the method according to the invention is suited for the synthesis of oxazolidinone compounds with interesting properties for use, for example, as pharmaceutics or antimicrobiotics.
• Polyoxazolidinones obtained by the method according to the invention are particularly suited as polymer building blocks in polyurethane chemistry.
• epoxy-terminated oligomeric oxazolidinones oligooxazolidinones
• Such epoxy-terminated oligomeric oxazolidinones are also suited for the preparation of composite materials.
• Epoxy-terminated oligomeric oxazolidinones may also be reacted with their NCO-terminated counterparts to form high molecular weight polyoxazolidinones, which are useful as transparent, high temperature-stable materials.
• Polyoxazolidinones with high molecular weight obtained by the method according to the invention are particularly suited as transparent, high temperature-stable thermoplastic materials.
• para-To ⁇ y ⁇ isocyanate purity 99%; distilled in a partial vacuum (200 mbar, 80 °C) and stored under argon at -4 °C prior to use, Acros Organics, Belgium.
• Diisocyanate 1 2,4-Toluenediisoyanate, >99 % 2,4-isomer, Bayer MaterialScience AG, Germany
• R-(+)-Styrene oxide was distilled in a partial vacuum (200 mbar, 80 °C) prior to use.
• Diepoxide 1 Bisphenol-A-diglycidylether (4,4'-isopropylidenediphenol diglycidyl ether, Epikote Resin 162), purity +99%, stored at room temperature, Momentive, Germany
• NMP N-Methylpyrrolidinone
• the 300 ml pressurized reactor used in the synthesis of polyoxazolidinones had a height (internal) of 10.16 cm and an internal diameter of 6.35 cm.
• the reactor was fitted with an electric heating jacket (510 watt maximum heating capacity).
• the counter cooling consisted of a U-shaped dip tube with an external diameter of 6 mm, which projected into the reactor to within 5 mm of the bottom and through which cooling water at approximately 10°C was passed. The water stream was switched on and off by means of a solenoid valve.
• the reactor was also fitted with an inlet tube and a temperature probe of 1.6 mm diameter, both of which projected into the reactor to within 3 mm of the bottom.
• the impeller agitator used in the examples was a pitched-blade turbine to which a total of two agitator stages, each with four agitator blades (45°) of 35 mm diameter and 10 mm height, were attached to the agitator shaft at a distance of 7 mm.
• pulse addition corresponding to the step-wise addition mode of the isocyanate, means that the isocyanate compound is added in individual steps, comprising a part of the total amount of the isocyanate compound, to the reaction mixture.
• IR In-situ Infrared
• the composition of the reaction mixtures was followed with a Bruker MATRIX-MF spectrometer equipped with a high-pressure attenuated total reflectance (ATR) IR fibre optical probe.
• the ATR IR fibre optical probe (3.17 mm outer diameter, 90° diamond prism with 1 x 2 mm basal area and 1 mm height as ATR element, 2 ⁇ 45° reflection of the IR beam, IR beam coupled via fibre optics) was fitted into the reactor in such a way that the diamond at the end of the optical probe was immersed entirely into the reaction mixture.
• IR spectra (average of 20 scans, if not stated otherwise) were recorded time-resolved in the region of 3500-650 cm “1 with a resolution of 4 cm “1 at 60 second time intervals (if not stated otherwise).
• the spectra were analysed with the software PEAXACT 3.1 - Software for Quantitative Spectroscopy and Chromatography, S'PACT GmbH using the Integrated Hard Model (IHM) method.
• the hard model for analysing the IR spectra of the reaction mixtures was created by linear combination of hard models for the single components monoisocyanate, oxazolidinone and isocyanurate.
• the hard model for the single components was created as follows:
• a 10 mL glass flask containing 5 mL propylene carbonate was immersed into an oil bath preheated to 160 °C.
• a background IR spectrum (average of 100 scans) was measured against air.
• the IR probe was then inserted into the glass flask in such a way that the diamond at the end of the optical probe was immersed entirely into the reaction mixture.
• the glass flask was capped with a rubber seal and another background IR spectrum was measured (average of 100 scans).
• monoisocyanate 1 (0.37 mL, 2.95 mmol, 5 mol% relative to propylene carbonate) was injected with a microliter syringe through the seal into the reaction mixture and several IR spectra were recorded of the resulting mixture.
• the relevant signals in the region 2150 to 2400 cm “1 were selected from a representative IR spectrum and the model refined to achieve an optimum fit between a superposition of the selected signals and the averaged IR spectra of the mixture.
• a 10 mL glass flask containing 0.5 mL propylene carbonate was immersed into an oil bath preheated to 160 °C.
• a background IR spectrum (average of 100 scans) was measured against air.
• the IR probe was then inserted into the glass flask in such a way that the diamond at the end of the optical probe was immersed entirely into the reaction mixture.
• the glass flask was capped with a rubber seal and another background IR spectrum was measured (average of 100 scans).
• a 10 mL glass flask containing 0.5 mL propylene carbonate was immersed into an oil bath preheated to 160 °C.
• a background IR spectrum (average of 100 scans) was measured against air.
• the IR probe was then inserted into the Schlenk flask in such a way that the diamond at the end of the optical probe was immersed entirely into the reaction mixture.
• the Glass flask was capped with a rubber seal and another background IR spectrum was measured (average of 100 scans).
• the turnover frequency (TOF1/2) was determined according to equation 1, TOF . " “ ⁇ : “ , “ : ⁇ (eq. l)
• n co,to is the molar amount of isocyanate in the reaction mixture after injection of the second isocyanate pulse
• nNco,ti/2 is the residual molar amount of isocyanate observed by in-situ IR spectroscopy at ti 2 after injection of the second isocyanate pulse
• n cat is the molar amount of catalyst in the reaction mixture after injection of the second isocyanate pulse.
• n fm oxA is the molar amount of oxazolidinone moieties at the end of the reaction and n fm icT is the molar amount of isocyanurate groups at the end of the reaction.
• Solid state IR analyses were performed on a Bruker ALPHA-P IR spectrometer equipped with a diamond probe head. A background spectrum was recorded against ambient air. Thereafter, a small sample of the oxazolidinone (2 milligrams) was applied to the diamond probe and the IR spectrum recorded averaging over 32 spectra obtained in the range of 4000 to 400 cm “1 with a resolution of 4 cm “1 .
• the software OPUS 6.5 was used for data treatment.
• the molar fraction of the two regioisomers in the oxazolidinone product was determined by HPLC chromatography (monooxazolidinones) or 3 ⁇ 4 NMR spectroscopy (polyoxazolidinones) as described below.
• the regioselectivity RS-OXA was then calculated according to the following equation 3 :
• XS OXA is the molar fraction of 5-substituted l,3-oxazolidin-2-one (5-OXA) moieties at the end of the reaction and X4-OXA is the molar fraction of 4-substituted l,3-oxazolidin-2-one (4-OXA) moieties at the end of the reaction.
• the HPLC analyses were carried out on an Agilent Technologies 1200 Series instrument equipped with an UV detector and a Waters SymmetryShield RPis column (particle size 5 ⁇ , pore size 100 A). The temperature of the column was kept constant at 40 °C throughout the measurement. A water-methanol solvent system (flow rate of 1.0 mL/min) was used for separation of the components of the reaction mixture. The reaction mixture (10 mg) and mesitylene (5 ⁇ ) were dissolved in methanol (1 ml) and a defined volume of the mixture injected onto the column. An isocratic condition with a water-to-methanol ratio of 60:40 was maintained for 20 min.
• the average chain length of the polyoxazolidinones was adjusted by the relative molar ratio of the diisocyanate and diepoxide used in the particular reaction.
• Equation 4 (eq.4) below gives a general mathematical formula to calculate the average chain length n in the oligomeric and/or polymeric product based on the molar ratios of diisocyanate and diepoxide compound employed.
• n 1 / [ ⁇ (amount of diepoxide in mol) / (amount of diisocyanate in mol) ⁇ - 1 ] (eq. 4)
• Equation 5 (eq. 5) below gives a general mathematical formula to calculate the average chain length n in the oligomeric and/or polymeric product based on the molar ratios of diisocyanate and diepoxide compound employed.
• n 1 / [ ⁇ (amount of isocyanate in mol) / (amount of epoxide in mol) ⁇ - 1 ] (eq. 5)
• the ratio of the two regioisomers in the polyoxazolidinone product was determined by l H NMR spectroscopy.
• a representative example of the polyoxazolidinone structure is represented by the formula (III) shown below.
• the formula weight (FW) of the end-groups and the repeating unit is given, based on
• the regioselectivity RS-OXA was calculated from the integrals of the signals Sl-1 andSl-2 using the following equation 6:
• GPC Gel permeation chromatography
• thermogravimetric analysis TGA
• the measurements were performed on a Mettler Toledo TGA/DSC 1.
• the sample (6 to 20 mg) was heated from 25 °C to 600 °C with a heating rate of 10 K/min and the relative weight loss followed in dependence of temperature.
• the software STAR 6 SW 1 1.00 was used. As decomposition temperature the inflection point of the sinuidal weight loss curve is stated.
• the glass transition point was recorded on a Mettler Toledo DSC 1.
• the sample (4 to 10 mg) was heated from 25°C to 250 °C with a heating rate of 10 K/min.
• the software STAR 6 SW 1 1.00 was used for data analysis.
• For determination of the glass transition temperature a tangential analysis method was used. The midpoint of the intersection point between the tangent at low temperature and the tangent in the mid temperature range and the intersection point between the tangent in the mid temperature range and the tangent at high temperature is stated.
• a glass flask (20 mL) was charged with 4-bromoanisol (381.5 mg, 2.04 mmol), ⁇ 13 ⁇ 4 (562 mg, 2.14 mmol), NiBr2 (22.3 mg, 0.10 mmol) and ethylene glycol (0.68 mL, 12.19 mmol).
• the mixture was stirred (600 rpm) at room temperature for 10 min using a magnetic stirrer bar of 0.3 cm length.
• the flask was then placed into a hot oil bath set to 180 °C for 20 minutes. The heating of the oil bath was then switched off and the reaction mixture cooled to room temperature within of 30 min.
• Dichloromethane 35 mL was added to the crude reaction mixture and the organic layer was washed three times with water and once with brine, dried over MgSO i, filtered and the solvent partially removed under partial vacuum. A brown highly viscous fluid was obtained, which was diluted with dichloromethane (ca. 2 mL). Diethylether (15 mL) was added to this mixture, while shaking the flask vigorously. A white precipitate was obtained, which was collected, washed two times with diethylether and dried in a partial vacuum to afford the product as a white solid.
• Example 1 Reaction of R-(+)-styrene oxide with para-tolyl isocyanate using [PPhs ⁇ p- C 6 H 4 (OMe) ⁇ ]Br (1-1) as catalyst
• a first pulse of para-to ⁇ y ⁇ isocyanate (0.388 g, 2.92 mmol) was added quickly (within of 2 s) and the reaction mixture stirred until completion of the reaction was indicated by disappearance of the isocyanate band.
• a second pulse of para-to ⁇ y ⁇ isocyanate (0.388 g, 2.91 mmol) was added quickly (within of 2 s) and the reaction mixture stirred until completion of the reaction was indicated by disappearance of the isocyanate band.
• a third pulse of para-to ⁇ y ⁇ isocyanate (0.388 g, 2.92 mmol) was added quickly (within of 2 s) and the reaction mixture stirred until completion of the reaction was indicated by disappearance of the isocyanate band.
• the heating of the oil bath was switched off and the reaction mixture cooled to room temperature within of 45 min. The chemical composition of the reaction mixture was analysed.
• HPLC analysis confirmed full conversion of R-(+)-styrene oxide and para-to ⁇ y ⁇ isocyanate.
• the chemoselectivity SOXA (HPLC) for the formation of the oxazolidinone compound was 100 %. Signals due to the presence of other side products like carbodiimids and homo-polymers of the epoxides were not observed.
• the regioselectivity RS-OXA (HPLC) towards the 5-oxazolidinone (5-OXA) regioisomer was 88 %.
• a first pulse of para-to ⁇ y ⁇ isocyanate (0.388 g, 2.92 mmol) was added quickly (within of 2 s) and the reaction mixture stirred until completion of the reaction was indicated by disappearance of the isocyanate band.
• a second pulse of para-to ⁇ y ⁇ isocyanate (0.388 g, 2.91 mmol) was added quickly (within of 2 s) and the reaction mixture stirred until completion of the reaction was indicated by disappearance of the isocyanate band.
• a third pulse of para-to ⁇ y ⁇ isocyanate (0.388 g, 2.92 mmol) was added quickly (within of 2 s) and the reaction mixture stirred until completion of the reaction was indicated by disappearance of the isocyanate band.
• the heating of the oil bath was switched off and the reaction mixture cooled to room temperature within of 30 min.
• the chemical composition of the reaction mixture was analysed. TOFi/2 with respect to conversion of the isocyanate was 580 h "1 .
• HPLC analysis confirmed full conversion of R-(+)-styrene oxide and para-tolyl isocyanate.
• the chemoselectivity SOXA (HPLC) for the formation of the oxazolidinone compound was 100 %. Signals due to the presence of other side products like carbodiimides and homo-polymers of the epoxides were not observed.
• a first pulse of para-to ⁇ y ⁇ isocyanate (0.388 g, 2.92 mmol) was added quickly (within of 2 s) and the reaction mixture stirred until completion of the reaction was indicated by disappearance of the isocyanate band.
• a second pulse of para-to ⁇ y ⁇ isocyanate (0.388 g, 2.91 mmol) was added quickly (within of 2 s) and the reaction mixture stirred until completion of the reaction was indicated by disappearance of the isocyanate band.
• a third pulse of para-to ⁇ y ⁇ isocyanate (0.388 g, 2.92 mmol) was added quickly (within of 2 s) and the reaction mixture stirred until completion of the reaction was indicated by disappearance of the isocyanate band.
• the heating of the oil bath was switched off and the reaction mixture cooled to room temperature within of 30 min.
• the chemical composition of the reaction mixture was analysed. TOFi/2 with respect to conversion of the isocyanate was 762 h "1 .
• HPLC analysis confirmed full conversion of R-(+)-styrene oxide and para-to ⁇ y ⁇ isocyanate.
• the chemoselectivity SOXA (HPLC) for the formation of the oxazolidinone was 100 %. Signals due to the presence of other side products like carbodiimides and homo-polymers of the epoxides were not observed.
• the regioselectivity RS-OXA (HPLC) towards the 5-oxazolidinone regioisomer was 80 %.
• Example 4 Reaction of R-(+)-styrene oxide with para-tolyl isocyanate using PPh4Br (1-3) as catalyst
• a first pulse of para-tolyl isocyanate (0.388 g, 2.92 mmol) was added quickly (within of 2 s) and the reaction mixture stirred until completion of the reaction was indicated by disappearance of the isocyanate band.
• a second pulse of para-tolyl isocyanate (0.388 g, 2.91 mmol) was added quickly (within of 2 s) and the reaction mixture stirred until completion of the reaction was indicated by disappearance of the isocyanate band.
• a third pulse of para-tolyl isocyanate (0.388 g, 2.92 mmol) was added quickly (within of 2 s) and the reaction mixture stirred until completion of the reaction was indicated by disappearance of the isocyanate band.
• the heating of the oil bath was switched off and the reaction mixture cooled to room temperature within of 30 min.
• the chemical composition of the reaction mixture was analysed. TOFi/2 with respect to conversion of the isocyanate was 552 h "1 .
• HPLC analysis confirmed full conversion of R-(+)-styrene oxide and para-tolyl isocyanate.
• the chemoselectivity SOXA (HPLC) for the formation of the oxazolidinone was 100 %. Signals due to the presence of other side products like carbodiimides and homo-polymers of the epoxides were not observed.
• the regioselectivity RS-OXA (HPLC) towards the 5-oxazolidinone regioisomer was ⁇ 78 %.
• Example 5 Reaction of R-(+)-styrene oxide with para-tolyl isocyanate using [P( «-Bu) i]Br (1-4) as catalyst
• a first pulse of para-tolyl isocyanate (0.388 g, 2.92 mmol) was added quickly (within of 2 s) and the reaction mixture stirred until completion of the reaction was indicated by disappearance of the isocyanate band.
• a second pulse of para-tolyl isocyanate (0.388 g, 2.91 mmol) was added quickly (within of 2 s) and the reaction mixture stirred until completion of the reaction was indicated by disappearance of the isocyanate band.
• a third pulse of para-tolyl isocyanate (0.388 g, 2.92 mmol) was added quickly (within of 2 s) and the reaction mixture stirred until completion of the reaction was indicated by disappearance of the isocyanate band.
• the heating of the oil bath was switched off and the reaction mixture cooled to room temperature within of 30 min.
• the chemical composition of the reaction mixture was analysed. TOFi/2 with respect to conversion of the isocyanate was 410 h "1 .
• HPLC analysis confirmed full conversion of R-(+)-styrene oxide and para-tolyl isocyanate.
• the chemoselectivity SOXA (HPLC) for the formation of the oxazolidinone was 100 %. Signals due to the presence of other side products like carbodiimides and homo-polymers of the epoxides were not observed.
• Example 6 Reaction of 1 ,2-epoxy-3-phenoxy propane with para-tolyl isocyanate using 1-1 as catalyst
• a first pulse of para-to ⁇ y ⁇ isocyanate (0.388 g, 2.92 mmol) was added quickly (within of 2 s) and the reaction mixture stirred until completion of the reaction was indicated by disappearance of the isocyanate band.
• a second pulse of para-to ⁇ y ⁇ isocyanate (0.388 g, 2.91 mmol) was added quickly (within of 2 s) and the reaction mixture stirred until completion of the reaction was indicated by disappearance of the isocyanate band.
• a third pulse of para-to ⁇ y ⁇ isocyanate (0.388 g, 2.92 mmol) was added quickly (within of 2 s) and the reaction mixture stirred until completion of the reaction was indicated by disappearance of the isocyanate band.
• the heating of the oil bath was switched off and the reaction mixture cooled to room temperature within of 30 min. The chemical composition of the reaction mixture was analysed.
• HPLC analysis confirmed full conversion of l,2-epoxy-3-phenoxy propane and para-to ⁇ y ⁇ isocyanate.
• the chemoselectivity SOXA (HPLC) for the formation of the oxazolidinone was 100 %. Signals due to the presence of other side products like carbodiimides and homo-polymers of the epoxides were not observed.
• the regioselectivity RS-OXA (HPLC) towards the 5-oxazolidinone regioisomer was 100 %.
• Examples 1 and 6 show that independent of the choice of the epoxide a similar rate is obtained.
• Example 7 Reaction of R-(+)-styrene oxide with para-tolyl isocyanate using [PPh ⁇ (cyclohexyl)]Br (1-6) as catalyst at a higher reaction temperature
• Example 3 was repeated as described above, whereby the reaction was conducted at a temperature of 200 °C.
• HPLC analysis confirmed full conversion of R-(+)-styrene oxide and para-to ⁇ y ⁇ isocyanate.
• the chemoselectivity SOXA (HPLC) for the formation of the oxazolidinone was 95%. Signals due to the presence of other side products like carbodiimides and homo-polymers of the epoxides were not observed.
• the regioselectivity RS-OXA (HPLC) towards the 5-oxazolidinone regioisomer was 85%.
• Example 8 Reaction of R-( +)-styrene oxide with para-tolyl isocyanate using PPh 4 Br (1-3) as catalyst at a higher reaction temperature
• Example 4 (comp.) was repeated as described above, whereby the reaction was conducted at a temperature of 200 °C.
• HPLC analysis confirmed full conversion of R-(+)-styrene oxide and para-tolyl isocyanate.
• the chemoselectivity SOXA (HPLC) for the formation of the oxazolidinone was 88 %. Signals due to the presence of other side products like carbodiimides and homo-polymers of the epoxides were not observed.
• Examples 3 and 7 show that independent of the reaction temperature the oxazolidinone product is obtained with a higher rate (TOF1/2), when phosphonium salts with an unsymmetric substitution pattern are used, in comparison to comparative examples 4 and 8, in which a phosphonium salt with a symmetric substitution pattern was used.
• TOF1/2 reaction temperature
• the regioselectivity towards the 5-oxazolidinone regioisomer obtained in examples 3 to 7 using onium salts according to the invention were higher compared to comparative examples 4 and 8.
• the reaction was performed in a 300 ml stainless steel autoclave as described above with a motor with a stirring power of 90 W.
• the reactor was charged with diepoxide 1 (BADGE, 15.0 g, 44.1 mmol) and catalyst 1-2 (154 mg, 0.42 mmol) and subsequently flushed three times with argon.
• Diepoxide 1 BADGE, 15.0 g, 44.1 mmol
• catalyst 1-2 154 mg, 0.42 mmol
• argon After addition of dry NMP (40 ml), the reactor was sealed and the mixture was heated to 200 °C under rapid stirring (1000 rpm). After 200 °C had been obtained, a solution of diisocyanate 1 (TDI, 7.3 g, 41.97 mmol) in dry NMP (15 ml) was added with an HPLC pump (10 ml pump head) over 3 h.
• TDI diisocyanate 1
• reaction mixture After an overall reaction time of 19 h (starting with the addition of diisocyanate 1), the reaction mixture was cooled to room temperature. The reaction mixture was poured into methanol. The precipitate was collected and washed three times with methanol and subsequently with diethylether. The obtained powder was dried at 5x 10 "2 mbar for 4 hours.
• the regioselectivity RS-OXA (NMR) towards the 5-substituted l,3-oxazolidin-2-one regioisomer was > 96 %.
• Example 9 shows that polyoxazolidinone compounds are obtained, when onium salts according to the invention are used as catalyst in the reaction of diisocyanate compounds with diepoxide compounds.
• Example 10 Reaction of 2,4-toluenediisocyanate (TDI) with 4,4'-isopropylidenediphenol diglycidyl ether (BADGE) using (1-1) as catalyst followed by reaction of the product with para-tolyl isocyanate
• TDI 2,4-toluenediisocyanate
• BADGE 4,4'-isopropylidenediphenol diglycidyl ether
• the reaction was performed in a 300 ml stainless steel autoclave as described above with a motor with a stirring power of 90 W.
• the reactor was charged with diepoxide 1 (15.0 g, 44.1 mmol) and catalyst 1-1 (0.2g, 0.44 mmol) and subsequently flushed with Argon.
• After addition of dry NMP (40 ml) the reactor was sealed and the mixture was heated to 200 °C under rapid stirring (1000 rpm). After 200 °C had been obtained, a solution of diisocyanate 1 (7.3 g, 41.97 mmol) in dry NMP (15 ml) was added with an HPLC pump (10 ml pump head) over 3 h.
• the regioselectivity RS-OXA (NMR) towards the 5-substituted l,3-oxazolidin-2-one regioisomer was > 95 %.
• Example 10 shows that polyoxazolidinone compounds are obtained, when onium salts according to the invention are used as catalyst in the reaction of diisocyanate compounds with diepoxide compounds followed by reaction of the obtained product with a monoisocyanate compound in the presence of the same catalyst.

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